Method of making piston-rings.



PETER DULK. JR... OF ELIZABETH, NEW JERSEY.

METHOD OF MAKING PISTON-RINGS.

No Drawing.

To all whom. it may concern Be it known that I. PETER DnLK, Jr., acitizen of the United States, residing in Elizabeth. in the county ofUnion and State of New Jersey, have invented certain new and usefulImprovements in Methods of Making Piston-Rings, of which the followingis a full and clear specification.

My invention relates to methods of making piston rings and has forobjects, first, to eliminate a number of operations heretofore thoughtnecessary in the manufacture of piston rings. thereby reducing the costof manufacture and increasing the output of a given equipment; second.to improve the accuracy of the rings and also the duality of the pistonrings with respect to their resistance to wear. thereby increasing thelife and efficiency of the rings.

My invention and the result accomplished by it will be best understoodby reference to some of the known methods of manufacturing piston rings.which comprise substantially the following steps:

1. The rings are usually cut from a long sleeve or cylinder which haspreviously been bored and reduced on its outer surface to approximatelythe required thickness. or they can be cast singly with a smallallowance for finishing.

2. Each ring is then reduced to approximately the required width byinserting it between oppositely revolving grinding disks.

3. Each ring is then split or cut obliquely at one point and its insidesurface is peened. and the bur formed by the first grinding operation isremoved with the file. The rings are now required to be reduced to theproper width of workingsurface, it being understood that the rings areout from the sleeves or cylinder over size in this respect. The width ofthe working surface is of extreme importance. This width must beaccurate and uniform in each ring and all the rings must be identicalwithin a small margin of error.

i. It thenbecomes necessary to flatten or straighten the ring since theformer operations have resulted in the free ends of the cut o split ringbecoming out of alinement.

5. The ring is placed flat against a magnetic chuck and is again reducedin width by means of an emery disk. The importance of the straighteningoperation (5) will now be seen inasmuch as ifthe ring did not lie flatagainst the chuck more material Specification of Letters Patent.

Patented Dec. 15, 1914.

Application filed April 15, 1914. Serial No. 831,924.

would be removed from some parts of the ring than from others.

6. The ring is then removed from the chuck and turned over, exposing itsother face. and the emery disk is again applied and the ring is reducedto a size permitting only the removal of a small quantity of materialfor the purpose of finishing the surfaces.

7. Before finishing. however, it becomes necessary to repeat thestraightening operation which. it must be understood, is a manualoperation. requiring the employment of skill.

The ring is then applied to the magnetic chuck for finishing and isground first.

on one side. then turned and ground on the other. This time. however,less material is removed.

9. For the second time it becomes necessary to remove the bur formed bythe grinding operations. This operation of removing the bur consists inplacing the ring on a rapidly revolving cone chuck and then applying thefile. first to one edge and then the other of the ring. It will be seenthat this is an operation of some danger to the operators fingers.inasmuch as the ring quickly takes up the movement of the chuck and mustbe promptly released. Among other advantages which I claim for my invention is the elimination of this second burring operation.

By my invention I propose to eliminate a number of operations byintroducing a single operation which performs all the functions of theoperations which I have described above number 4 to 9. inclusive.Moreover the single operation which 1 propose to introduce will takeless time and consequently be cheaper than any one of the operationswhich I am enabled to eliminate.

According to my method, the ring blanks are prepared in the usual way bycutting from the sleeve or cylinder or by any other way and roughground, split, burred and if desired peened in the usual way. I thentake the ring and reduce the working surface to the desirednvidtn byapplying pressure to the opposite faces of the ring. By this singleoperation the ring is straightened, re duced to size and the surfacesfinished. Furthermore. the rings produced by my method will possess aquality not found in rings of the prior art.

As is well known,

lOO

piston rings are made usually of cast iron,

which is spongy and porous. It is obvious duce the width of the ring bypressure With-' out seriously affecting its radial thickness.

While I propose to adopt as the means for pressing the rings a powerpress having parallel die faces, I do not wish to limit myself to thisparticular pressure device. Without departing from the spirit of myinvention I may use pressure rollers or any other suitable means. Byusing flattening dies of sufiicient size I shall be able to press ringsof any diameter from the largest to the smallest. Furthermore it isimmaterial whether the rings be concentric or eccentric. one advantageof the method I employ relates to the elimination of the emery disks forperforming the final operation of reducing the rings to size. As is Wellknown, grinders of this nature must be kept inconstant adjustment foraccurate work, in' View of the Wearing away of the grinding surface.Pressure devices, on the other hand,

such as those I have mentioned will maintain their adjustment for acomparatively proper shape,

long period. Therefore, losses from failure to keep the machinery inadjustment will be less if my method is employed.

I find that by bending the ring to a separating its ends after thesplitting operation, and then thereafter compressing it the ring willbecome set with its ends separated, giving the required tension whencompressed. I thereby eliminate the operation of peening Which hasheretofore been one of the methods used for spreading the ends andgiving the ring the desired tension.

I claim:

1. In methods of making piston rings, a finishing operation, comprisingcompressing the ring axially, whereby the Working surface is reduced tothe desired Width, the material of the ring is compacted, and the ringis flattened.

2. The method of making piston rings, which comprises splitting thering, expanding the ring to separate its ends, and then compressing thering axially whereby the metal becomes set with the ends separated, and,whereby the required tension is-imparted to the ring when it iscontracted to operative. form.

PETER DULK, JR. Witnesses:

RAY T. ERNST, W. H. KNIGHT.

